Robotized tele-echography has been developed since the mid-nineties to compensate for the insufficient numbers of ultrasound (US) experts and their regrouping in large medical care facilities centers, resulting in a growing number of medically isolated areas. Ultrasound imaging is a low cost, reliable and non-invasive technique used routinely in hospitals; however, it is an expert-dependent technique, meaning that the experts can only make a diagnosis when they are able to combine anatomical knowledge with the current orientation of the probe and its position on the patient’s body and the analysis of the ultrasound images. The teleoperated TER system allows the expert physician to move a virtual probe in a manual, natural, and unconstrained way and safely reproduces this motion on the distant site where the patient is examined by means of a slave robot holding the real probe.
The Tele-echography Platform
The system includes three parts linked to each other: the expert station (i.e. the operator), the patient station and the communication link that enables data exchange between the two stations.
The expert (Master) station: the specialist uses a haptic fictive ultrasound probe to control the robot end-effector holding the real ultrasound probe. The haptic device allows the expert to feel the interactions between the distal environment (i.e. the patient’s body) and the real ultrasound probe.
The patient (Slave) station: the robot carrying the real ultrasound probe is positionned and maintained on the patient by an assistant. The robotic probe holder system reproduces the medical expert’s gestures during the tele-echography procedure thanks to the haptic device.
The communication link: the communication network links the expert station to the patient station. Depending on the requirements and availability at the sites involved, a tele-operation system may use different types of communication links (e.g. WLAN, Satellite). In addition, a videoconferencing system is used for visual and auditory interactions between the expert, the patient and the assistant, and to transfer the ultrasound images from the patient station to the expert station.
According to Fetal tele-echography using a robotic arm and a satellite link(Copyright 2005 ISUOG. Published by JohnWiley & Sons, Ltd.), the robotic tele-echography works well.
P.Arbeille and his colleagues conduct a research in their paper: Method Tele-echography was performed from our hospital (expert center) on 29 pregnant women in an isolated maternity hospital (patient site) 1700 km away, and findings were compared with those of conventional ultrasound examinations. At the patient site, a robotic arm holding the real ultrasound probe was placed on the patient’s abdomen by an assistant with no experience of performing ultrasound. The robotic arm, remotely controlled with a fictive (expert) probe, reproduced the exact movements (tilting and rotating) of the expert hand on the real ultrasound probe.
Results In 93.1% of the cases, all biometric parameters, placental location and amniotic fluid volume, were correctly assessed using the tele-operated robotic arm. In two cases, femur length could not be correctly measured.
Conclusion Tele-echography using a robotic arm provides the main information needed to assess fetal growth and the intrauterine environment within a limited period of time.